Reading mechanism of a dobby

ABSTRACT

Reading system for a pattern card used to control a dobby. The reading needle extends through guide means which are caused to reciprocate in a direction parallel with the path of movement of the pattern card and to do so in such relationship to the movement of the needles toward and away from the pattern card that when the needles engage the pattern card they are moving with it at the same speed as the pattern card and when they are retracted they are returned to the place of beginning. Thus, it is possible to move the pattern card continuously at a constant speed or a speed coordinated to the guide moving means. Thus damage otherwise occurring at the sprocket openings of the pattern card is diminished and the tendency for the needles to punch or mar the pattern card by their points is also diminished.

United States Patent 1191 Wic r 1451 Nov. 19, 1974 READING MECHANISM OF A DOBBY 3,381,719 5/1968 Favre 139/68 Inventory Walter Oberrieden 3,680,601 8/l972 Palau 139/331 Swltzefland Primary Examiner-Henry S. Jaudon [73] Assignee: Staubli Ltd., Horgen-Zurich, Attorney, Agent, or Firm-Woodhams, Blanchard &

Switzerland Flynn 22 F'l d: F b. 20, 1973 l e 57 ABSTRACT [21] p 334l56 Reading system for a pattern card used to control a Related US. Application Data dobby. The reading needle extends through guide 3] continuatiommpan f 232359, March 8, means which are caused to reciprocate in a direction 1972, abandone parallel with the path of movement of the pattern card and to do so in such relationship tothe movement of [30] Foreign Application P i it D t the needles toward and away from. the pattern card Mar. 10 Switzerland 3494/71 that when the needles engage the pattern card they are moving with it at the samespeed as the pattern [52] us. ca 139/68 139/329 139/331 and"thett they are 'etteeted they are returned 511 Int. Cl noic 1/22 1503c 1/24 the Phtee 0f heghthhtg- Thus it is Peeeihte meve the [58] Field of Search 139/66 68 330 331 pattern card continuously at a constant speed or a l39/332 speed coordinated to the guide moving means. Thus I damage otherwise occurring at the sprocket openings [56] References Cited of the pattern card is diminished and the tendency for the needles to punch or mar the pattern card by their UNITED STATES PATENTS points is also diminished. 2,644,488 7/1953 Ptarrwaller 139/68 2,690,770 10/1954 Ruti 139/68 5 Claims, 5 g Flgures Ill/Ill].

PATENTEL SUV 1 91974 SHEEI 2 BF 4 READING MECHANISM OF A DOBBY This application is a continuation-in-part application of Ser. No. 232,859, filed Mar. 8, 1972 now abandoned.

FIELD OF THE INVENTION The invention relates to the reading mechanism of a dobby with a patternlike perforated, running pattern card and reading needles which read these perforations and control the shed-forming mechanism and which are movable in their axial direction approximately vertically toward and away from the pattern card for the reading.

BACKGROUND OF THE INVENTION Modern high-speed dobbies (Swiss Pat. No. 120 488) are controlled weft logically, namely the patternforming movement for the heddle frames for two successive picks always is read from the pattern card and the necessary preparations are made to effect suitable movement of the shed-forming mechanism. By reading two pick controls, namely both the pick which must be inserted next and also the last, already inserted, pick, it becomes possible for the weaving machine to be switched over at any time from the forward run to the reverse run.

If the speed of the machine is increased, the available time for the intermittent conveying of the card and the inserting and removing of the reading needles from perforated pattern cards is further shortened even though for these movements there is at best only a short period of time available of an entire operating cycle for one pick insertion. This disadvantage is met upon an increase of the pick number of the weaving machine, particularly the shed-forming portion thereof, by driving the reading needles and the card with a somewhat higher power so thatall movements are performed with the needed rapidity. The reading needles are driven by springs or weights which urge the needles in so far as they hit nonperforated points of the pattern card against said points of said card. This increased force and the greater impact speed of the needles on the card soon leads to an undesired piercing through the card or to deformation of either or both of the needles and the card. This results in defects in the resulting weave. Furthermore the teeth of the conveyor roller for the pattern card often destroy the feed holes along the edges of the pattern card because the cards react against the teeth with greater inertia force during shortened switching times.

It is a primary object of this invention to increase the pick number of the shed-forming machine per unit of time without increasing the stress on the perforated pattern card.

The primary object is attained according to the invention with a reading mechanism of the mentioned type which is characterized in that the conveyor mechanism of the pattern card moves continuously and the reading needles are supported in guides which move the needles while their points are engaged with the card during the entire reading operation at the same speed as the pattern card and are then moved back during the lifted-off condition.

The conveyor roller according to the invention moves the pattern card at a substantially constant speed without intermediate stopping so that the needle points which stand on the card, or which extend through the card, move synchronously therewith and are then returned to their initial position after the operation has ended and the needles are in a lifted off conpattern card by means of only small forces which protect the feed holes because only the friction and no inertia forces act thereon. It is also possible to diminish the force exerted by the weights and springs which drive the reading needles against the pattern card and are engaged by said pattern card, because the advancing time of the card and the thereafter following entering 'time of the reading needles into the card are now combined into time which is all available only yet for the entering of the needles. Thus, the needles do not have to accelerate as quickly as previously which prevents an undesired piercing through the pattern card or a deformation of same.

Referring now to the drawing: V

FIG. 1 is a side view of a schematically illustrated reading mechanism;

FIG. 2 illustrates a driving mechanism for the pattern card, the guides and the lifting off bars;

FIG. 3 is a top view of two guides corresponding t the section line IVIV in FIG. 2; I

FIG. 4 is a diagramatic illustration of the movements of various parts of the dobby; and

FIG. 5 is an enlarged perspective view of the push needle lift mechanism.

DETAILED DESCRIPTION Referring now to FIG. 1, the conveying mechanism for the pattern card 3 consists of a conveyor roller 4. The lowered reading needles 6 engage the holes 5 of the pattern card. Said needles slide in guides 7 and are positioned approximately vertically with respect to the pattern card. The support rods are identified with reference numeral 8. The reading needles 6 hang on the support rods which areoperated on one side by the back and forth swinging conventional push knives 9 and on the other side of the up and down swinging conventional lift-off bars 10. The support needles themselves control the hooks of a dobby in a conventional manner.

The pattern card is now moved continuously by the conveyor roller at a constant speed or at'a speed which is variable according to the operating cycle of the pick insertion. The points of the reading needles move now with the same speed as the pattern cards because the guides themselves move back and forth. It is indicated in the drawing which inclined position the guides and needles can assume.

The possible operations are the following:

The reading needles which feel the perforated pattern card remain during the forward movement of the card on, or in the holes of, the pattern card and the ends thereof which are in engagement with the card synchronously move with said card in the movingdirection thereof. They are then lifted off from the card at the end of its operating cycle and spring back into their initial position. The pattern card can thereby be moved on continuously at an even speed or item be movedat a variable speed according to the operating cycle, that is during the operation of one pick. The reading needles for reading the even and those for reading the'uneven picks can simultaneously move with the pattern card and spring back into the initial position. However, it is also possible for the reading needles for the even and uneven picks to move with the pattern card at different times and to return into the initial position. In a known dobby with four reading needles for reading the new and the last pick, they can move simultaneously with the pattern card or they can move at different times with the pattern card.

FIGS. 2 to 5 illustrate in more detail the structure. by which the movement of the needles is related to the movement of the pattern card. The lifting-off bars are constructed as rakes whereby the lifting-off bars serve to lift up the two reading needles and 16 and the lifting-off bars 11 serve to lift up the needles 17 and 18. The lifting-off bars 10 are extended between two notches of the rake whereas the lifting-off bars 11 extend through the notches. The push knife 9 moves the push needles and 27 to the right. The push knife 12 moves the push needles 26 and 28 also to the right.

In the arrangement illustrated in FIGS. 2 and 3 only the portion pertaining to the functioning of the reading needles 17 and 18 will be described, it being understood that the associated structure for the reading needles is identical to that described hereinbelow. The reading needle 17 is swingably secured to the push needle 27. The reading needle 18 is swingably secured to the push needle 28. Accordingly, the up and down movement of the push needles 27 and 28 will cause a corresponding up and down movement of the push needles 27 and 28.

The push needles 27 and 28 are driven up and down by a pair of vertically spaced and vertically driven lift bars 11A and 11B (FIGS. 2 and 5). The lift bars have a plurality of notches 11C therein into which are received the push needles 25 and 26 which are operated for vertical movement by the lift bars 10A and 10B (See FIG. 5). The notches 11C permit the push needles 27 and 28 to be moved without influencing or controlling the push needles 25 a'nd26 and the notches 10C permits the push needles 25 and 26 to be moved without influencing or controlling the push needles 27 and 28.

Referring now to FIG. 2, a drive shaft 30 has a pair of cams 33 and 43 mounted thereon for rotation therewith. The cam 33 has an elliptical-like cam surface 33A. The cam 43 has an elliptical-like cam surface 43A but the major axis thereof is at approximately a right angle to the major axis of the cam surface 33A. A lever A is pivotally secured to a shaft 37. A cam following roller 34 is rotatably secured to the lever 35A and engages the cam surface 33A. Thus, a rotation of the shaft 30 and the cam 33 will effect a pivotal movement of the lever 35A corresponding to the contour of the cam surface33A. A spring 36 is provided between a fixed member 36A and the lever 35A to keep the roller 34 in engagement with the cam surface 33A.

A lever 35B is pivotally secured at one end to the free end of the lever 35A. A guide mounting bracket 21 is pivotally secured to a shaft 38. The guide mounting bracket 21 is generally an inverted U-shape, the

leg 21A upon a rotation of the drive shaft 30. A pair of vertically spaced guides 7 are secured to the leg 21A of the guide bracket 21. Each of the guides 7 have a plurality of pair of holes 21C (see FIG. 3) therethrough and a plurality of slots 21D (see also FIG. 3) therein. The holes 21C are slightly larger in diameter than the push needles 17 and 18 and receive the push needles 17 and 18 therein so that a pivoting or rocking of the bracket 21 will effect a pivoting of the reading needles 17 and 18 relative to the push needles 27 and 28. The slots 21D receive the push needles l5 and 16 therein so that the movement of the leg 21A will not effect a movement of the reading needles 15 and 16. Similarly, a pair of vertically spaced guides 13 are secured to the leg 21B of the guide bracket 21. Each of the guides 13 have a plurality of pairs of holes 21E (see FIG. 3) therethrough and a plurality of slots 21F (see also FIG. 3) therein. The holes 21E are slightly larger in diameter than the push needles l5 and 16 and receive the push needles 15 and 16 therein so that a pivoting or rocking of the leg 213 will effect a pivoting of the reading needles 15 and 16 relative to the push needles 25 and 26. The slots 21F receive. the push needles l7 and 18 therein so that the movement of the leg 218 will not effect a movement of the reading needles 17 and 18. The

pivoting or rocking motion of the leg 21B is controlled bracket 21 being pivotably secured to the shaft 38 at by a cam and lever arrangement like the cam 33 and levers 35A and 35B arrangement shown in FIG. 2.

A generally horizontally arranged 'V-shaped lever 47 is pivotably secured to the shaft 47 at the apex thereof and has a cam following roller 44 secured to the end of one leg of the V. The roller 44 engages the cam surface 43A of the cam 43. A lever 48 is secured to the end of the other leg of the V and the lift bars 10A and 10B are secured to the lever 48 and are movable up and down in accordance with the movement of the cam surface 43A. A spring 46 is provided between a fixed surface 46A and a leg of the lever 45 to urge the roller 44 into engagement with the cam surface 43A. The movement of the lift bars 11A and-11B are controlled by a similar but not illustrated V-shaped lever arrangement.

A gear 31A is secured to the drive shaft 30 and is driven thereby. A gear 318 is engaged with the gear 31A and is driven thereby. A shaft 31C is connected to the gear 31B and has a gear 32 mounted thereon. The gear 32 engages the conveyor roller 4 associated with the belt 3 so that the belt 3 is driven by the gear train 31A, 31B and 32 from the drive shaft 30. Thus, no matter what the speed of rotation of the drive shaft 30, the belt 3 will be moved at a corresponding rate of speed fixed by the aforementioned gear train.

OPERATION The drive mechanism-which is illustrated in FIG. 2 operates as follows.

The conveyor roller 4 is driven continuously by the drive shaft 30 through the gears 31A, 31B and 32. From this results a continuous movement of the pattern card 3.

The cam 33 is driven by the drive shaft 30 and the roller 34 on the lever 35A is engaged with the cam surface 33A. The spring 36 presses the roller 34 against the cam surface 33A. During a rotation of the shaft 30, the guides 7 perform a back and forth movement which, in their movement to the left, have the same speed as the conveyor roller 4 of the pattern card 3. The reading needles 17 and 18, which are supported in the guides 7, thus remain in the holes of the pattern card and move at the same speed therewith.

Only after a lifting up of the reading needles 17 and 18 through the lifting bars 11A and 11B are the guides 7 again moved back to the right by the spring 36. In the described movement, the axes 37 and 38 are to be considered as fixed axes. The guides 7 thus pivot about the axis 38.

The movement of the guides 13 are controlled in the same manner. 1

The cam 43 is also driven by the shaft 30 and the roller 44 of the two-arm V-shaped lever 45 rolls engages the cam surface 43A. The lever 45 is pivotable about the fixed axis 47. The lever 48, which is hinged to one arm of the lever 45, carries the lifting bars 10A and 108. In the illustrated position the lifting bars 10A and 10B are in their highest position. The-spring 46 presses the roller 44 against the cam surface 43A.

The movement mechanism for the lifting bars 11 is the same.

which the needles l5 and 16 are guided, while the needles l7 and 18 extend through the slots 21F. The guides 7, however, have slots 21D for the needles l5 and 16.

FIG. 4 illustrates the movement diagrams of the individual parts: Curves A and B illustrate the heddle frame movement during a normal weaving operation; Curves C and D illustrate the movement of the upper push knife 12 and the lower push knife 9, respectively, for the push needles 26, 28 or 25, 27, respectively; Curves E and F illustrate the movement curve of the lifting bars 11 or 10; and the curves G and H illustrate the movement of the needle guides 7 or 13. At the end the last curve I shows the movement of the pattern card 3.

FIG. 2 illustrates the situation at the time X.

From curves G and I, one can see that the pattern card moves at the same speed as the needle guides 7. During the forward run of the dobby, it is to be noted that during the time that the lifting bars 11 are lifted off, the lifting bars 10 are simultaneously lowered, while the push knives 12 and 9 remain at rest until the lifting bars have completed their movement. If, however, the dobby would be switched into reverse, namely a time movement in FIG. 4 to the left, the lifting bars 10 and 11 would have to stand still while the lower push knife 9 and then the upper push knife 12 carries out its pushing motion. I

The embodiments of the invention in which an exclusive property or priviledge is claimed are defined as follows:

1. In a reading mechanism of a dobby having a patterned perforated, moving pattern card and reading needles which read said perforations and control a 20 As FIG. 3 illustrates, the guides 13 have holes 21E in shed-forming mechanism, the improvement comprisa plurality of horizontally aligned, axially and vertically movable push needle means, said push needle means being vertically movable between first and second positions, said push needle means, when in said first position, being positioned to effect an operation of said shed-forming mechanism; t plurality of vertically aligned and axially movable reading needle means, one each being swingably connected to one of said push needle means, each of said reading needle means being adapted to move axiallytoward and away from and engage a perforation in said perforated pattern card to thereby control the vertical movement of said push needle means; pusher means directly engaging said push needle means when said push needle means is in said first position to thereby effect an operation of said shedforming mechanism, said pusher means by-passing said push needle means when said push needle means is in said second position; conveyor means for supporting said pattern card for movement; first drive means for driving said pattern card for continuous movement; guide means for engaging and guiding said reading needle means; and second drive means connected to said guide means to effect a positive movement of said reading needle means from a starting position simultaneously with said pattern card while engaged therewith, said second drive means including means for returning said reading needle means to a position above said starting position only when said reading needle means are disengaged from said pattern card. 2. The improvement according to claim 1, wherein said returning means for returning said guide means and said reading needles to said starting position includes means for supporting said guide means for movement in the opposite direction from said pattern card during said return movement.

3. The improvement according to claim 1, wherein thenumber of reading needles per heddle frame is two for both a forward run and a backward run.

'4. The improvement according to claim 3, wherein said second drive means drives said guide means at the same speed as said first drive means drives said perforated pattern card.

5. The improvement according to claim 3, wherein said second drive means includes means for driving said guide means for each pair ofreading needles at differing times relative to said continuous movement of said pattern card. 

1. In a reading mechanism of a dobby having a patterned perforated, moving pattern card and reading needles which read said perforations and control a shed-forming mechanism, the improvement comprising: a plurality of horizontally aligned, axially and vertically movable push needle means, said push needle means being vertically movable between first and second positions, said push needle means, when in said first position, being positioned to effect an operation of said shed-forming mechanism; a plurality of vertically aligned and axially movable reading needle means, one each being swingably connected to one of said push needle means, each of said reading needle means being adapted to move axially toward and away from and engage a perforation in said perforated pattern card to thereby control the vertical movement of said push needle means; pusher means directly engaging said push needle means when said push needle means is in said first position to thereby effect an operation of said shed-forming mechanism, said pusher means by-passing said push needle means when said push needle means is in said second position; conveyor means for supporting said pattern card for movement; first drive means for driving said pattern card for continuous movement; guide means for engaging and guiding said reading needle means; and second drive means connected to said guide means to effect a positive movement of said reading needle means from a starting position simultaneously with said pattern card while engaged therewith, said second drive means including means for returning said reading needle means to a position above said starting position only when said reading needle means are disengaged from said pattern card.
 2. The improvement according to claim 1, wherein said returning means for returning said guide means and said reading needles to said starting position includes means for supporting said guide means for movement in the opposite direction from said pattern card during said return movement.
 3. The improvement according to claim 1, wherein the number of reading needles per heddle frame is two for both a forward run and a backward run.
 4. The improvement according to claim 3, wherein said second drive means drives said guide means at the same speed as said first drive means drives said perforated pattern card.
 5. The improvement according to claim 3, wherein said second drive means includes means for driving said guide means for each pair of reading needles at differing Times relative to said continuous movement of said pattern card. 